This invention relates to microwave apparatus for heating food and other material bodies, and more particularly to microwave heating apparatus using multiple energy coupling elements each with an independent microwave power source.
In the ordinary microwave oven a single high power microwave generator such as a magnetron tube is used in conjunction with a single coupler or antenna element, and the energy fills the entire oven cavity. There are difficulties at present with various schemes to use a plurality of low power sources such as microwave solid state devices. Although it is possible to combine the individual power outputs of a few low power sources into a single transmission line, the total power that can be produced is limited and is best utilized as the equivalent of a single higher power source. If multiple coupling elements are used in conjunction with a plurality of independent low power microwave sources, the problem to be overcome is that the individual sources may destructively interfere with one another. With the advent of solid state microwave oscillators, which at present are low power sources of microwave energy, it is apparent that it would be desirable, however, to have a microwave heating apparatus employing a plurality of independent low power sources in a useful, simple, and efficient manner.